It is known to employ "on the go" gear shifters in motorized apparatus, in accordance with which movement of a gear shift handle from a restrained, gear engaged position to a gear changing position simultaneously acts to disengage a clutch, and vice versa. In prior art devices of this nature, the gear changing position is defined by an elongated slot along which the gear shift handle is freely movable. A plurality of detent opening openings are provided in communication with the slot on one transverse side only thereof; each detent opening defines a predetermined gear ratio, and provides the means for restraining movement of the gear shift handle. Where there are no restrictions on the length of the slot, a relatively large number of detent openings that are widely spaced may be provided, and the margin of error in selecting any desired gear ratio is small. However, in certain apparatus there may be limitations to the slot length, and the detent openings are correspondingly arranged closely together, whereby selection between them becomes less certain.